The final deathbed scene from "Man of La Mancha" with Peter O'Toole and Sophie Loren singing "To Dream The Impossible Dream" with the rest of the cast. I remember it having the same effect on a group of long haired, bearded, bikers dressed in leathers and denim cut-offs and looking tough right up 'til that point.

The difference between fiction and reality? Fiction has to make sense.

Here's the set up for those unfamiliar with the ep/show. Pizza delivery boy Fry is accidentally frozen for 1000 years, wakes up, makes a robot friend (bender), hijinks ensue. in this ep fry and his friends are roaming the ruins of old new york, and come across the remains of fry's dog Seymour. que flashbacks of Fry finding him as a puppy. Seymour following him around, waiting outside his job, and after fry is frozen trying to alert the family that something is wrong, but it doesn't work, etc.

Fry's genius scientist relative tells him they could clone Seymour and he could have his dog back. Bender gets jealous and more fun happens. Bender gives in in the end. and as they are prepping the remains for cloning, Fry finds out this 3 year old dog was 18 when he died. So he says, "Wait, Seymour lived 15 years without me. he lived a long life wihtout me around. He doesn't need me. lets leave him rest in peace". and then they cut to this

They sort of ruin it all (or make it better, which is my opinion) by having Seymour actually living a full and happy life with Fry, albeit a Fry who came back from the future. It's complicated, but the events are there in Bender's Big Score.

Anyway, tear jerker endings for me?

Well, the ending of the film adaptation of Nineteen Eighty-Four is one. The music, a slow instrumental version of Oceania, 'Tis for Thee, and John Hurt quietly thinking "I love you" (to Big Brother) while weeping gets me every time.

There's also the funeral scene in Backdraft...

Oh, and the ending of Evangelion 2.22: You Can (Not) Advance. The music gets me.

Not just that, but the fact that it manages to combine a happy ending, a sad ending, and a horrifying ending simultaneously. Shinji saves Rei from the inside of an Angel in one of the most heartwarming scenes in the series (and is probably the first time that Shinji Ikari, of all people, grows a bloody spine!), but in the process, he ends up triggering the very apocalyptic event he was supposed to prevent. In a word, Oops.

And then, there are two of the Doctor's regenerations from Doctor Who. The Fourth becoming the Fifth...

And the Tenth becoming the Eleventh. Unfortunately, I can't find that on YouTube. The BBC must've done a sweep or something...Bugger.

I'm definitely one of the wobbly lower lip brigade for all sorts of scenes, particularly where someone is crying in the scene - my empathy chip kicks in big time when someone else is upset. But I have to agree with Bouncy on this one which is guaranteed to make me blub:

Well, one scene guaranteed to get me misty-eyed is the ending from Metal Gear Solid 3: Snake Eater. The basic setting is 1964, and an operative called Naked Snake ('naked' in that he has a minimum of equipment for a stealth mission) is sent on a mission into a remote part of the USSR with multiple objectives: rescue a scientist called Sokolov; destroy the nuke-launching tank Sokolov designed called the Shagohod; kill the evil Russian renegade Colonel Volgin; and kill Snake's own mentor, the Boss, a famous female soldier who had defected to the USSR.

Snake had succeeded in his mission, partly with the help of an agent called EVA, who tells Snake not only the truth about her own mission (she wasn't working for the KGB, but for the Chinese), but also the Boss, who was actually working for the US government all the time. He's learnt, effectively, that the government screwed her over and sacrificed her so that they could get a hold of a vast resource of funds known as the Philosopher's Legacy from Volgin.

By the way, that name, Big Boss? If it sounds weird to you, Big Boss is the villain of the first two Metal Gear games, and Metal Gear Solid 3 was actually the first game to look at Big Boss' past, and why he turned against the US.